#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=2e5+1000;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
vector<pair<LL,LL>>v;
int main(void)
{
  cin.tie(0);std::ios::sync_with_stdio(false);
  LL t;cin>>t;
  while(t--){
    LL n;cin>>n;
    v.clear();
    if(n==3){
        cout<<2<<"\n";
        cout<<3<<" "<<2<<"\n";
        cout<<3<<" "<<2<<"\n";
        continue;
    }
    LL temp=n;
    LL sum=0;
    for(LL i=n-1;i>=3;i--){
        if(i*i>temp){
            sum++;
            v.push_back({i,n});
        }
        else{
            while(i*i<=temp){
                sum++;
                v.push_back({n,i});
                temp=(temp+i-1)/i;
            }
            sum++;
            v.push_back({i,n});
        }
    }
    while(temp>=2){
        sum++;
        temp=(temp+2-1)/2;
        v.push_back({n,(LL)2});
    }
    cout<<sum<<"\n";
    for(auto i:v){
        cout<<i.first<<" "<<i.second<<"\n";
    }
  }
return 0;
}
